Usefulness of immunohistochemical staining in diagnosing a challenging case of oral primary syphilis

Clinicians involved in the diagnosis of mucocutaneous diseases should be aware that syphilis is still prevalent among humans and its accurate may require substantial clinical evaluation. Herein, we report a case primary presenting as an isolated ulcer on upper left labial oral mucosa. The lesion exhibited no specific features could have been easily mishandled. An important observation was presence satellite-enlarged lymph node submandibular area, which highly indicative syphilis. Histopathological examination specimen obtained by punch biopsy revealed suggestive immunohistochemical staining with antitreponemal antibody confirmed detection numerous Treponema pallidum specimen.